Help With the Jargon

RayG

Well-Known SatelliteGuys Member
Original poster
Oct 27, 2008
26
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I have been reading a lot of posts to try and get an understanding of the technology employed in Dishnetwork.
This is a summary of what I think is correct. Please tell me if I am off base but do so nicely. I am very fragile psychologically.:eek:

1. MPEG-2 and MPEG-4 are digital compression technologies. They are neither video formats (like NTSC or PAL) nor are they signal encoding techniques.

2. Any digital signal can use either but MPEG-2 would use more bandwidth than MPEG-4

3. In the world of Dishnetwork Locals all the signals via satellite are digital at the delivery point whether they began as a local analog or local digital signal.

4. Most TV's process the digital signal from the receiver into an analog signal for display.

5. Thus the terms "analog" and "digital" (at least in reference to locals) are useful primarily to distinguish between the two original signals.

6. The term analog means the analog-encoded signal (current NTSC television) and is used because it refers to the network signal as it is broadcast to antenna users.

7. Likewise digital signal (current DT/only game in town in a few months) refers to the digitally-encoded signal that stations broadcast to antennas.

8. The programming carried on this (digital) signal may be standard definition (SD) or high definition (HD) but it is the same signal (channel).

9. There are some specialty channels (not networks) that are entirely high definition programming but these are the exception.

10. There are not and probably won’t be network feeds that are exclusively high definition. If for no other reason because an HD feed hogs the whole signal where a station can put multiple SD feeds.

11. You can watch HD programming on any receiver/TV combination but if the receiver and TV are not capable of HD, it will be downgraded to SD.

12. All of Dishnetwork’s receivers can process MPEG-2. A few can handle MPEG-4.

13. The requirement for an MPEG-4 receiver on the Eastern Arc is because all of the signals will be MPEG-4 encoded at some point. It does not have anything (directly) to do with analog/SD/HD programming.

14. HD programming is more likely to be compressed via MPEG-4 for the reasons stated above but there is no technical requirement to do so.

15. If EA (or any other) programming is compressed via MPEG-4 then you need an MPEG-4-capable receiver even if you never plan to watch an HD program.

Ok, release the hounds.:hungry:
 
I have been reading a lot of posts to try and get an understanding of the technology employed in Dishnetwork.
This is a summary of what I think is correct. Please tell me if I am off base but do so nicely. I am very fragile psychologically.:eek:

1. MPEG-2 and MPEG-4 are digital compression technologies. They are neither video formats (like NTSC or PAL) nor are they signal encoding techniques.


Correct. If you want to be more specific, in the case of Dhish network, MPEG-2 and MPEG-4 are generally refering to video compression technologies

2. Any digital signal can use either but MPEG-2 would use more bandwidth than MPEG-4


Correct again. Technically a digital video signal can be compressed with any compression technology, Dish Network currently only uses MPEG-4 and MPEG-2. The downside to MPEG-4 is that it takes significantly more processing, both at the compressing end, and the receiving end, resulting in higher costs for equipment.

3. In the world of Dishnetwork Locals all the signals via satellite are digital at the delivery point whether they began as a local analog or local digital signal.


If I'm reading your statement corectly, you are again correct. Just I case I'm not, let me say it a different way. Dish receives local channel signals from the channel provider as either a digital feed, or as an analog feed. It is then converted to digital at an uplink center (and compressed using the applicable MPEG technolgy) then sent to a satellite to be sent to your receiver.

4. Most TV's process the digital signal from the receiver into an analog signal for display.


Incorrect, in most situations the receiver is converting the signal to analog for the television to display. The only exception to this is when a High definition receiver is connected to a television via an HDMI or DVI cable. You can still get a full HD signal on your TV via analog Component cables.

5. Thus the terms "analog" and "digital" (at least in reference to locals) are useful primarily to distinguish between the two original signals.


Generally when people refer to anolog vs. digital locals, they are refering to Over The Air Locals (via an antenna). Most people will talk about the difference as either having their locals being in HD, or just in Standard Definition.

6. The term analog means the analog-encoded signal (current NTSC television) and is used because it refers to the network signal as it is broadcast to antenna users.


If you are talking about local channels, yes generally. However the term "analog" is far to broad to generalize down to NTSC.

7. Likewise digital signal (current DT/only game in town in a few months) refers to the digitally-encoded signal that stations broadcast to antennas.


Again, if you are only talking about the field of local channels, yes, however not every discussion of analog vs. digital refers to locals, so this may be too broad of a genrealization. You could say digital OTA (Over the Air) singnal refers to the digitally encoded signal that stations broad cast to antennas

8. The programming carried on this (digital) signal may be standard definition (SD) or high definition (HD) but it is the same signal (channel).


Sort of...The digital over the air signal, although it only occupies the same bandwidth as one channel, may be carrying multiple feeds. Usually in digital there is an HD and SD feed encoded into one channel (and they are generally the same programming, although the formating may be different). Digital Over the Air channels may carry other "sub-channels" as well

9. There are some specialty channels (not networks) that are entirely high definition programming but these are the exception.


Not entirely sure what you are trying to state here as far as channels vs. networks. If you clarify the question I may be able to answer it.


10. There are not and probably won’t be network feeds that are exclusively high definition. If for no other reason because an HD feed hogs the whole signal where a station can put multiple SD feeds.


False, As stated above, a local network can carry whatever feeds they want, as long as they don't exceed the bandwidth for one channel.

11. You can watch HD programming on any receiver/TV combination but if the receiver and TV are not capable of HD, it will be downgraded to SD.


Nope, Only HD receivers can decode high definition signal. In the case of HD locals, Dish will encode them as SD before being uplinked to the satellite for non-HD receivers (sometimes resulting in unfavorable cropping due to HDs 16x9 aspect ration compared to SD at 4x3)

12. All of Dishnetwork’s receivers can process MPEG-2. A few can handle MPEG-4.


Correct, The ones that can process MPEG-4 all have model numbers that begin with VIP. The are the VIP211,211K,411,222,622,722,612(soon to come:VIP222K,722K, and 922).

13. The requirement for an MPEG-4 receiver on the Eastern Arc is because all of the signals will be MPEG-4 encoded at some point. It does not have anything (directly) to do with analog/SD/HD programming.


Correct. MPEG-4 compressed streams can be HD or SD. In reverse MPEG-2 can be either as well, however MPEG-4 compression requires less bandwidth for an equivalent quality signal.


14. HD programming is more likely to be compressed via MPEG-4 for the reasons stated above but there is no technical requirement to do so.


Correct, on dish network. However if were are talking about HD signals for an antenna, they will usually be MPEG-2 (as this was the standard for ATSC broadcasts). Dish will convert most of these to MPEG-4 before they are uplinked to conserve bandwidth.

15. If EA (or any other) programming is compressed via MPEG-4 then you need an MPEG-4-capable receiver even if you never plan to watch an HD program.


Correct.

Ok, release the hounds.:hungry:

I don't think I abused you too thoroughly. If you need further info on any of these feel free to ask. I wasn't always sure if you were talking about Dish Locals, OTA locals, or Dish network service in general for some of your questions which made them hard to answer clearly as they are all significantly different.
 
Thanks for your response. A couple of comments to clarify (I hope!)

Generally when people refer to anolog vs. digital locals, they are refering to Over The Air Locals (via an antenna). Most people will talk about the difference as either having their locals being in HD, or just in Standard Definition.

I was trying to sort out the difference in the locals provided by Dish. For instance take WFRV, the Green Bay CBS affiliate. Dish provides the "analog" (the same as the NTSC OTA channel 5) on channel 9331 on 110. WFRV-DT, Channel 56* (the same as the ATSC OTA channel 56*) on DishChannel 5161 (from 61.5)

*I know that TV's are programmed to display this as Channel 5 but wanted to be technically accurate.

Now DishChannel 5161 may have HD programming if the station broadcasts HD programming. If the station decides to have 5 regular subchannels then they can't have HD programming at the same time. So calling 5161 "HD" seems to be misleading as is calling 9331 "SD" - since it isn't the station's digital signal at all. This is different than say, the History Channel HD (5313) which is exclusively HD programming (or at least mostly).




Sort of...The digital over the air signal, although it only occupies the same bandwidth as one channel, may be carrying multiple feeds. Usually in digital there is an HD and SD feed encoded into one channel (and they are generally the same programming, although the formating may be different). Digital Over the Air channels may carry other "sub-channels" as well



Not entirely sure what you are trying to state here as far as channels vs. networks. If you clarify the question I may be able to answer it.

False, As stated above, a local network can carry whatever feeds they want, as long as they don't exceed the bandwidth for one channel.

But they can't carry HD and multiple SD at the same time can they?




Nope, Only HD receivers can decode high definition signal. In the case of HD locals, Dish will encode them as SD before being uplinked to the satellite for non-HD receivers (sometimes resulting in unfavorable cropping due to HDs 16x9 aspect ration compared to SD at 4x3).

Really? In the case of OTA non-HD digital TV sets can display HD programming (with letterboxing etc. because of the different aspect ratios. Unless you are saying that the HD broadcast is accompanied by an identical SD signal. I just thought that an HD signal uses the whole channel by itself.
 

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